Communication networks can be built in many different network topologies, such as a ring, mesh, linear, linear chain, tree, and the like. Conventionally, network protection is provided for at layers one and below, such as through SONET, SDH, and the like. Typical protection schemes can include Automatic Protection Switching (APS), Uni-directional Path Switched Rings (UPSRs), two and four fiber Bi-directional Line Switched Rings (BLSRs), and the like. Traditionally, networks are typically not protected using ring protection schemes at layer two (e.g., Ethernet) and above. For example, Ethernet-based access and aggregation networks are typically designed in a tree structure, and thus lack network protection.
Modern networks, such as access and aggregation networks, are moving towards Ethernet as the universal medium. Ethernet standards are evolving towards carrier-grade performance, and equipment providers today provide various different solutions for Ethernet-based network protection. For example, layer one protection can be provided through Ethernet-over-SONET or Ethernet-over-SDH solutions. To increase the bandwidth with the Ethernet-over-SONET and Ethernet-over-SDH leads to higher cost. At layer two, various solutions have been presented, such as Rapid Spanning Tree Protocol (RSTP), and Spanning Tree Protocol (STP). The main problems with these type of path protection scheme are: (1) switching time in response to a fault is relatively slow, (2) cannot offer QoS because of in-deterministic tree; and (3) complex circuitry.
Another form of providing protection switching in a layer-2 network is an Ethernet ring Protection Switching (ERPS) which is formed only of Ethernet bridges as per ITU-T G.8032v1 or v2. This network protection scheme is only restricted for bridges/switches within the chain or loop of the network. Whenever the network has to expand i.e. for a Metropolitan Area Network (MAN), the protection scheme has to include one or more aggregation devices for data transfer. The standard ITU-T G.8032 is for Layer 2 Ethernet device. There is no ring protection switching for a Non-ERPS device. And hence, connecting an ERPS chain to the Non-ERPS device will not ensure the ERPS protection of the Non-ERPS device.
For the reasons stated above, which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for a protection switching method and system of a node having communication failure in a ring, in a communication network.